1. Field of Invention
This invention relates to the field of snorkeling equipment. More specifically, this invention relates to snorkeling equipment that has been modified for use by a person who is unable to scuba dive because of certain physical limitations, but who nonetheless desires the recreational experience of swimming completely submerged in the water, as is the case in scuba diving.
2. Description of Prior Art
Certain people are physically unable to scuba dive because their ears cannot take the pressure of the greater depths, or because they have difficulty breathing the compressed gases used in breathing tanks. Moreover, scuba diving presents other obstacles to enjoyment. For example, scuba diving equipment can be expensive to own or rent, and the safe operation of such equipment requires training.
The recreational experience of completely submerged swimming, however, could be had if there were snorkeling equipment that permitted submerged swimming at depths of five feet or less, a range of depth where water pressure would be physically tolerable and air could be comfortably drawn into the lungs in lieu of compressed gases. The improved snorkeling equipment of this invention satisfies this recreational need.
Snorkeling equipment that is commonly available for recreational use generally consists of the following components: (1) a face mask with an adjustable rubber strap, (2) a rigid, J-shaped air tube, the short, curved end of which is fitted with a rubber mouthpiece, and (3) a rubber tether that secures the air tube to the rubber strap of the face mask so that the air tube freely depends therefrom when not in use. Although styles and materials may vary, snorkeling equipment must have these components, the basic features of which are constrained by the equipment""s function as breathing apparatus designed to enable the swimmer""s face to be completely submerged during swimming. To facilitate swimming, rubber or plastic swim fins may be provided as part of basic snorkeling equipment.
Because of the snorkeling equipment""s basic functional design, the swimmer must swim along the water surface so that the long, straight end of the air tube clears the water surface and allows the swimmer to draw air into his or her mouth. Only the swimmer""s face and the ventral side of his or her body remain submerged. Although the air tube could be lengthened to allow the swimmer""s head and body to be completely submerged, this modification is not practical because the air tube when in use must remain more or less perpendicular with the water surface, and consequently, the range of movement of the swimmer""s head and body would be severely limited by the allowable angle of the air tube relative to the water surface.
The improved snorkeling equipment of this invention has the following objectives: (1) to enable the swimmer to submerge his or her head and body a few feet beneath the water surface, (2) to enable the swimmer to swim freely beneath the water surface without concern for the position of the air tube, (3) to enable the swimmer to draw in and expend out air with ease, and (4) to provide the swimmer with snorkeling equipment of relatively simple construction and inexpensive parts for recreational use. These and other objectives will be apparent from the description below of the invention""s preferred embodiments.
Others have made modifications to snorkeling equipment that are similar to some of the components of this invention in an effort to achieve the foregoing objectives. None of the prior art, however, describes, teaches, or suggests the novel combination taught by this invention. Nor does any of the prior art satisfactorily address all of the foregoing objectives.
U.S. Pat. No. 5,622,165 to Huang describes a snorkel diving device with a special floating disc that keeps the air tube above water level. Similarly, U.S. Pat. No. 5,351,681 to Hudson describes another design for a floating disc. Other designs that incorporate some sort of floating structure for maintaining the air tube above water are seen in U.S. Pat. No. 3,370,586 to Aragona, et al., and in Japanese Application No. 2-169393 to Tanaka.
Each of the foregoing designs lacks a lightweight, compact device that can provide a continuous flow of air to the swimmer so that the swimmer does not have to rely only on his or her diaphragm muscles to draw air from the atmosphere through the air pipe and down several feet of hose. It would be desirable for the swimmer to be able to draw in air with ease, notwithstanding the fact that he or she is completely submerged in water and has to draw air through a long hose connected to the air tube. When underwater, a swimmer""s diaphragm must work against the pressure of water. Moreover, the length and diameter of the hose can present difficulties for breathing. The longer or narrower the hose is, the more work the diaphragm has to perform to draw in a sufficient volume of air.
Others have attempted to provide a suitable means for providing a continuous flow of air to the swimmer so that the swimmer does not have to rely only on his or her diaphragm muscles to draw air from the atmosphere through the air pipe and down several feet of hose. None of these solutions are satisfactory, however.
U.S. Pat. No. 5,535,734 to Lu, et al. discloses an optional fan blade assembly. (See FIG. 6 and Col. 4, lines 26-36.) This fan blade assembly is wind-driven. Looking at the drawing figure depicting the assembly, it is difficult to see that this assembly would provide a significant flow of air to the swimmer. For one thing, the small fan blade assembly, being disposed inside the narrow breathing tube, would not have a sufficient volume of air to propel. Moreover, the large fan blade assembly protruding through the top of the breathing apparatus is entirely dependent on wind action, which is unpredictable. Indeed, the more wind there is to drive the large fan blade assembly, the rougher the water will be, and the less stable and more prone to capsizing the floating structure will be.
Lu et al. teaches away from the use of gasoline-powered air pumps and other mechanically driven devices because of the known risks of mechanical failure from use of the device in water and contamination of breathing air from engine exhaust. (See Col. 1, lines 38-52.) These disadvantages are inherent in the invention of U.S. Pat. No. 4,832,013 to Hartdorn, which discloses the use of a gasoline-powered air compressor. As seen in the disclosure, this design must be able to eliminate excess engine heat, noxious exhaust gases, and water accumulation. (See Col. 2, lines 27-59.) As a result, the design is overly complicated and cumbersome.
U.S. Pat. No. 5,471,976 to Smith discloses a battery operated air pump. Smith employs the air pump, however, in conjunction with a xe2x80x9ccontractible tube conceptxe2x80x9d which accumulates an air supply between breath. (See Col. 2, lines 20-28.) As indicated in the disclosure, without the contractible tube concept, Smith""s portable electric air pump and battery system could not deliver the necessary flow of air. Smith also employs a low pressure regulator to regulate the flow rate and pressure for safe breathing. (See Col. 2, lines 38-40.) Like Hartdorn, Smith improves upon the conventional air pump used in the diving art. An air pump, whether gasoline-powered or battery-powered, however, does not meet the objectives of this invention.
The improved snorkeling equipment of this invention has a rigid air tube that is fitted to a float so that the air tube is kept afloat in a stable position more or less perpendicular to the water surface. Inside the floating structure is a centrifugal fan which draws the air in from the air tube and forces it to the swimmer""s mouthpiece via several feet of flexible tubing. A purge valve system consisting of (1) a purge valve intake fitted between the flexible tubing and the mouthpiece, through which fresh air passes to the lungs and (2) a reservoir purge valve outlet fitted on the mouthpiece, through which stale air passes from the lungs directly into the water instead of flowing back up the air tube, ensures an unidirectional flow of air from the air tube to the mouthpiece.